1. Mail Conversation System Enhancements
   - Added pending import functionality for mail import retries with automatic retry mechanism
   - New `lhc_mailconv_pending_import` table for tracking failed mail imports
   - Manual import interface for retrying failed email imports
   - Improved IMAP retry logic for handling temporary failures

2. Message Masking and Security
   - Added message ghosting for sensitive information protection when guardrails are enabled
   - Operators without permission to see full messages will not see just-sent messages
   - Enhanced regex rules with optional name field and optional replacement variable
   - Additional masking options for PII protection
   - Improved guardrails validation for sensitive information

3. Widget Theme Configuration
   - Added `wtop` option for widget position from top spacing control
   - Enhanced widget positioning options for better layout flexibility

4. Tab Navigation and UX
   - Improved tab state persistence for chats and mails
   - Direct API implementation for remembering tab states
   - Enhanced tab navigation across multiple interfaces

5. Pre-chat Form Conditions
   - Added conditions support for maintenance mode in pre-chat forms
   - Enhanced validator logic for conditional maintenance mode display

6. Developer Documentation
   - Comprehensive copilot instructions reorganization
   - Added detailed integration points documentation
   - New data flows, testing strategies, and security model documentation
   - Domain-specific guides for API, auth, bot, caching, config, data-layer, departments, events, extensions, routing, UI, and users

7. Bug Fixes and Improvements
   - Improved error handling for robustness and better user experience
   - Enhanced cache management and clearing functionality
   - Various sync and performance improvements

For update just follow standard update procedure. For manual update it's update_343.sql

## What's Changed
**Full Changelog**: https://github.com/LiveHelperChat/livehelperchat/compare/4.75v...4.76v